What You Don't Know About the Wild Animals in Your City

We share our cities and suburbs with the furred and the feathered, but our understanding of them is fraught with misinformation. An excerpt from The Urban Bestiary provides a modern perspective on the wildlife we take for granted or even despise.

The practice of assembling bestiaries — compendiums of animal lore and knowledge — began in medieval times. They were lavishly illustrated volumes, lettered by monastics on vellum, edged with hand-mixed colors and gilt. They blended medieval science — what was believed to be factually true about each animal — with unreservedly fanciful descriptions.

Penned in the 12th century, the Aberdeen Bestiary’s entry for beavers exhibits the classic medieval bestiary components of observation, imagination and allegory. The beaver is accurately described as possessing a tail that is flat like a fish’s and fur that is soft like an otter’s. The animal was prized for its testicles, which were said to contain a potent liquid that could cure headache, fever and “hysteria.” (This liquid would have been castoreum, located in a small glandular sac at the base of the tail on both male and female beavers.) It is noted, impossibly, that to keep from being killed by a hunter, a beaver would castrate itself and toss its testicles in the hunter’s path.

We may chuckle over the misguidedness of beaver testicle tales, but our own cultural/zoological mythology is fraught with misinformation every bit as false as the beaver castration story. Nature books, television shows and conservation organizations educate us about remote wild and endangered species. Very often we know a great deal more about the Chinese giant panda or the lowland mountain gorilla than we do about the most common of local creatures, say the eastern gray squirrels in our backyards.

As urban dwellers, we find ourselves unmoored — bereft of the knowledge of local creatures, plants and soil that were a necessity of life just a couple of generations ago.

It is time for a new bestiary, one that engages our desire to understand the creatures surrounding our urban homes, helps us locate ourselves in nature and suggests a response to this knowledge that will benefit ourselves and the more-than-human world.

Pigeon

The official common name of the pigeon was recently changed from rock dove to rock pigeon. I preferred the term rock dove, which served as a reminder — and a surprise to some — that pigeons really are doves. People tend to separate them in their attitudes.

Doves are seen as clean in feather and heart, gentle, peaceful, calming, even holy somehow, and they have the prettiest blue eyelids. Pigeons are viewed as grimy, poopy, pestilential. They suffer the indignity of being utterly commonplace in human habitats.

Although Darwin’s finches have all the fame, Darwin wrote far more about pigeons than he ever wrote about the Galapagos finches or all of the island birds put together. It is common knowledge that pigeons were important to Darwin but less commonly known that pigeons were also beloved by Darwin. His studies led him down the road of personal obsession, where he kept a private dovecote and hobnobbed below his class with the pigeon fanciers of London.

I doubt that Darwin would have been surprised by the recent study published in the journal Science demonstrating math competence in pigeons.

Researchers in the Department of Psychology at New Zealand’s University of Otago began by teaching pigeons to order the numbers 1, 2 and 3. Images would appear on a touch screen, and the pigeons learned to peck the images in ascending numerical order.

Next, they were tested with a more abstract rule. Presented with pairs of images containing anywhere between one and nine objects, the pigeons again had to determine ascending order — if they were shown a group of four things and a group of seven, for example, they were supposed to peck the group of four first.

“Remarkably,” said lead author Damian Scarf, “the pigeons were able to respond to these novel pairs correctly.” And even more remarkable to primate-biased humans? “Their performance was indistinguishable from that of two rhesus monkeys that had been previously trained on this task.”

Pigeons can navigate by the stars. Why should we be flummoxed when we learn they can count to nine?

Abby Diamond

Opossum

The opossum has a white face that looks ghostly in the night, and lots of teeth — 50 teeth, more than any other North American mammal and about the same number as a Tyrannosaurus rex. But as far as being vicious or somehow dangerous, opossums are neither.

Opossums sleep up to 20 hours a day, out of which five hours are REM-cycle sleep, implying that opossums dream, even more than humans do. Opossums’ favorite foods are things we would like to have eradicated from our homes and yards: mice, rats, cockroaches, other large insects and spiders, slugs and carrion.

Opossums “seem dumb,” and they “seem dangerous.” We have to use “seem” with opossums because we know so little about them. But opossums are moderately to highly intelligent, ranking above domestic dogs on task tests. They are believed to be about as intelligent as pigs.

One of the problems with our modern opossum perception lies in our opposing circadian rhythms. They are from another kind of world, the night world, the place where in both mythology and psychology our own human anxieties are magnified, where we feel a sense of mystery. The opossum doubtlessly feels the same when it stumbles unwittingly into our world. A quiet, nocturnal animal beneath a bright, electric light and a shrieking human or an aggressive dog or a wandering urban coyote? Such moments inspire one of the opossum’s most singular behaviors.

When it finds itself in the most dire of circumstances, an opossum will fall into a state that mimics sudden death. This zoological strategy is not uncommon in insects, but it is rare in mammals. The opossum lies perfectly still and seemingly stiff, with its eyes closed; eventually, a musky, death-scented liquid will ooze from its mouth and the glands near the anus. This state will last for some minutes at least, and up to several hours.

Although you cannot even see the movement of breath in the breast, the opossum’s metabolism does not actually slow. Eventually, the opossum will twist its soft black ears all around, listening, and sniff the air. It will lift its funny head ever so slightly and have a peek around. When it deems all is well, it will amble off to perceived safety, no faster than usual.

Abby Diamond

Mole

Moles are reputed to taste terrible, possibly because of the increased hemoglobin that allows them to maintain oxygen balance in their subterranean haunts. So when a mole is killed by another animal, it is usually left lying. If you are fortunate enough to find a freshly dead mole, I would encourage you to embolden yourself in the noble role of urban naturalist and take a close look. (Moles are very clean and don’t carry diseases that affect humans; just wash your hands afterward.)

Running your hand over the dead mole’s coat, you will discover that mole fur is not just chinchilla-soft but also reversible — it has no nap, so the hair follicles are not directional, and the individual hairs can move in every direction. When a mole presses forward or back in its tight earthen tunnel, the fur accommodates; it is literally impossible for a mole to be rubbed the wrong way.

The thin, translucent layer of skin over the mole’s eyes is a permanent covering. Moles are not blind, but they are almost blind. The snout is soft, long and highly innervated, made for finding insects and grubs by feel. The front paws are large and spade-shaped, turned out for swimmer-like paddling through the soil, and tipped with substantial claws.

As with most perceived pests, moles are with us because we create a perfect place for them. The soil around our homes and parks is soft, free of big rocks and, in the case of gardens, nutrient-rich, with layers of mulch and compost that encourage the insects and grubs that moles love.

Overall, a mole in a garden is far more beneficial than harmful. Moles eat insects and their larvae; devour slugs, cutworms and white grubs; and sometimes even prevent harmful insect outbreaks. Beneath our beloved grass and flowers, they work in the depths, turning, tilling, aerating and fertilizing the soil.

Our crazed response to the presence of molehills could be perceived as disproportionate. Simple initial efforts to eradicate moles become obsessions, and efforts escalate from traps and poison to propane and sometimes even dynamite. Gardeners lie awake, figuring, plotting. It’s only a 7-inch mammal, really, the mole. And the damage? The proverbial molehill.

A typical suburban lot is populated, tunneled and mounded by just one male mole, or perhaps by two females. When a mole dies, or simply leaves your yard, it is likely another mole will come. Unless you want to live a vigilant, mole-killing life forever, you might as well just keep the mole you have.

We might delight in our newfound tolerance — moles are singular creatures from a subterranean world, a reminder that when we move and till and beautify the soil, we must do it by working alongside wild nature, not by overriding it. Any other approach is misguided and might also make us insane.

Abby Diamond

Squirrel

No creature demonstrates the human schizophrenia regarding urban wildlife better than the squirrel. In studies of backyard wildlife, squirrels rank as both the most desirable animal and the most hated nuisance animal.

Squirrel strife is nothing new. Ratatoskr, a squirrel in Norse mythology, spends his days running up and down Yggdrasil, the World Tree. Some sources picture a wounded Yggdrasil chewed up and down one side by the sharp-toothed Ratatoskr. And the tree itself? She spends much of her day grumbling, annoyed to distraction.

I have been this world tree, grumbling in bed just before dawn while a pair of Ratatoskrs nesting in the attic cornice right behind my sleepy head chew my house to pieces.

Squirrels are not, as some like to say, “just rats with bushy tails.” The workings of the squirrel’s bushy tail
actually create a squirrel social system that separates it from any other rodent. Their fluffy, swishy tails are the very heart of squirrel life, and their function is even more complex than that of the New World monkeys’ prehensile tails.

Here are some of the ways that a squirrel uses its tail: for balance while running; as a rudder while jumping; as a parachute; to cushion a fall; for warmth; for shade (held overhead like a parasol — the family name, Sciuridae, means “shade-tail”); as an umbrella; to swaddle young; to confound and scare off intruders; and as a surprisingly complex form of squirrel-to-squirrel communication. There is a whole repertoire of communiqués conveyed in the different twitches and swishes.

In addition to tail language, squirrels exhibit complex aural vocalizations. They possess a profound spatial memory, used to recover the nuts they bury as scatter-hoarders. They discover through tireless trial and error the one slender route into an attic. In spite of our best efforts to keep them from our bird feeders, not to mention an entire commercial industry devoted to this end, they outwit us constantly, using multistep problem-solving that is beyond the capability of most mammals and probably some humans.

Abby Diamond

Rat

It is common for people who find a fat brown rat in the basement to claim it is evil and as “big as a cat.” But rats rarely grow to weigh a full pound, and from tip to tail, an average one measures about 10 inches. And unless cornered, they are typically gentle and will avoid humans.

Although they dwell in the muckiest areas of urbania, rats are clean; they spend far more time cleaning and preening than humans do. The diseases that may be passed from rat to human are contracted by contact with concentrations of rat feces or urine or by being bitten (though, of course, the vast majority of infectious diseases contracted by humans come from contact with other humans).

In some countries, bubonic plague is still an issue, and it is passed between rats and humans by flea vectors (though not in North America). There has never been a case of a human in North America contracting rabies from a rat.

Still, they cause a lot of trouble. They chew through electrical wires and tunnel into homes and buildings. They reproduce wildly, sometimes within our walls. Rats will eat any animal smaller than they are: baby birds, small reptiles, fish, baby squirrels and rabbits.

Rats are fascinating and intelligent and make wonderful pets. They learn their names, come when called, bond readily with individual humans, play games like a dog and snuggle to sleep on laps or in pockets.

While laughter was long believed by ethologists to be a behavior limited to humans and, perhaps, the higher primates, recent studies show that young rats appear to laugh when they are tickled. They don’t emit the high laughter sounds when their backs are tickled, just when their tummies are — like human children.

And compelling new research by neuroscientists at the University of Chicago shows that rats may actually exhibit true altruism. When one rat was locked in a small Plexiglas cage within a larger cage, the rat in the big cage often worked tirelessly to release its imprisoned rat colleague, without any reward and whether or not it was acquainted with the confined rat.

When a pile of the rats’ favorite treat (milk chocolate chips!) was also placed in the larger cage, the free rat would not eat all the chips herself but would liberate the caged rat and share the chocolate. After the imprisoned rat was released, they would run around the cage together, jumping and chirping, as if rejoicing. Then, yes — to the chocolate.

The Wild Guest Book

Find out who your wild neighbors are, and learn to read their tracks, with this easy do-it-yourself project.

A tracking box can help you learn to identify tracks in your backyard. Make a wood frame out of 4‑by‑6s (tracking schools recommend a minimum of 4 feet by 8 feet) and fill it with sand. Play sand is great — it is light and lump‑free, and especially good for small birds. Construction sand or beach sand works, too. Dampen the sand so that it holds a shape without becoming runny.

Try visiting tracks as they age, as they fill with debris, as they are affected by weather. If no wild animals come, then practice with domestic ones. Try walking your dog through the box when he is hungry, when he is full, when he has to pee, when he doesn’t.

A box is best because it offers a controlled, contained substrate, but you can still benefit from the idea by leaving damp sand or soil edges around your garden. I have experimented with these loose‑form tracking boxes at the borders of our koi pond (sprinkled wildly with raccoon tracks) and our vegetable garden (mouse, squirrel, rat, opossum) and beneath our cherry tree (more of all of the above) — all of them small wild entries into the loveliest guest book I have ever kept.